Cushioning structure



July 4, 1950 H. c. FLINT 2,514,214 v cusHIoNING STRUCTURE Filed April 15, 1946 @Y l l A A A A i6 1Q f5 O12 n 12 H 15. BY L i6 NZ Patented July 4, 195o 2,514,214 cUsinoNiNG STRUCTURE Hyland C. Flint, Akron, Ohio, assignor to The Firestone Tire & Rubber Company, Akron, Ohio, a corporation of Ohio Application April 15, 1946, Serial No. 662,225

This rinvention relates to cushioning structures,

and more especially, it relates to the cushions of seats, s'uch as are employed in passenger automobiles, buses and railway and trolley coaches. However, its utility is not limited to the situations mentioned, and the principles of the invention advantageously may be employed in the construction of mattresses and similar appliances.

The chief objects of the invention are to provide an improved cushioning structure comprising two diiferent kinds of resilient supporting or cushioning elements; to provide a combination of two different cushioning elements to effect efcient cushioning Within a limited space, specically, a space of limited height; to provide a cushion of the character mentioned wherein the volume of one of the cushioning elements is reduced and a saving in cost is achieved; to provide a cushioning structure of the character mentioned wherein the cushioning elements are so arranged as to achieve superior circulation of air, whereby heat in the structure is dissipated; and to provide a cushioning structure capable of many variations in its cushioning characteristics.

According to the invention, the foregoing and other objects are achieved by the novel combination of two inherently different types of resilient elements, which elements mutually cooperate to achieve the contemplated function of the cushioning structure of the invention in a superior manner. One of the-resilient elements employed is composed of latex foam rubber. The other resilient element of the structure is a plurality of parallel, upwardly arched, transversely flat wire spring units, the same being a commercial product shown and described in the Kaden PatentNo. 2,002,399, issued May 21, 1935.

Both of said elements require certain amounts of space for efiicient operation and to provide maximum comfort to the user of the cushion. Moreover,l both elements are inherently capable of considerable variation in resilience or yieldability during deformation or'deflection, which results in compression of the rubber element and tension in the spring elements. The variability of the rubber structure arises from, (a) variation of density as the result of variations in the time consumed in whipping air bubbles into the rubber latex during processing thereof, prior to vulcanization, (b) variation in the height (thickness) of the rubber element. and (c) the number and size of cavities or recesses that are formed in the element. The -variability of the spring unit arises from 'four causes, namely; (a) the gauge of the wire of which the unit is composed,

3 Claims. (Cl. 155-179) (b) the height of the arc midway between the fixed ends of the unit, (c) the distance apart of said iixed ends, and ('d) the radius of the turns in the sinuosities of the spring wire, or, differently stated, the number of sinuosities in the spring unit.

It is inherent in the foamed rubber unit that the greater the height of the unit the less density is required, with the result that there is less sta.- bility, and a tendency to roll, both of which features are undesirable in a cushion or mattress. Conversely, reduction in the height of the unit requires greater density of structure with resulting hardness and loss of shock and vibration absorbing ability. l

Each wire spring unit derives its characteristic physical qualities from its method of fabrication. This transversely at spring is composed of Wire and formed into -sinuosities or undulations, and is given a permanent arcuate set by being tempered while coiled in a relatively small arc or roll, In use it is spread open by force into a relatively large arc and its ends anchored a determinate distance apart where they act as pivots. The height of the arc midway between the pivots and the distance apart of the latter determines the resistance to deection of the spring. Generally, two inches is considered the maximum height for the arc. It is usual in spring units of the character described that in practical use the vertical distance of travel of the middle of the arc is greater than the height of the arc above the chord that subtends the arc. In other Words, an arc having e height of two inches might require 'a travel distance of from 3 to 4 inches if spring units alone, unassisted by other elements, are employed to support the weight imposed upon the cushion or mattress. Thus spring units of this type are not entirely satisfactory for use as the sole resilient elements in cushions of relatively low height, since such springs require too great a distance ot travel if they are to provide the desirable soft effect required. f

As previously explained, the foam rubber cushion also is inefficient in a low cushion. However, by combining the two different elements in a novel manner, it is possible to produce an efilcient cushion of low height due to the increased number vof variables involved.

The invention is more particularly described hereinafter, by way of example, having reference to the accompanying drawingof which:

Fig. 1 is a fragmentary plan view of a, cushioning structure embodying the invention, a part Y thereof being broken away and in 4 Referring to the drawing, there is shown a cushioning structure that advantageously may be employed in the seats of motor vehicles, railway and trolleycoaches, and other environments y where personal comfort while sitting'is desired. It is also within the purview of the invetnion to' employ the principles thereof'in mattresses and the like to assure comfort while reclining'. v'

As shown in the drawing, the cushioning structure comprises a rigid base member III of oblong shape having rounded corners. Said base member conveniently may be made of wood because of its light weight and low cost. Mounted uponthe base I is Ia plurality of wire spring units II-I I of the Kaden type aforementioned, each of which unitsis secured to the said base by` hinge clips I2, I2 in which the terminal portions of the unit are pivotally received. The hinge clips I2 are mounted adjacent two opposite `margins of the base I0, and the spring units As is clearly shown in- Each spring is transversely fiat, and is composed of a succession of sinuosities or undulations, as

previously explained.

Superposed upon the 'base member It and spring elements I I is a body of resilient material.

specifically, vulcanized latex foam rubber, which body is designated as a whole bythe numeral Il. Said body is molded to the general shape of the cushion, and is formed on its under side withl a plurality of arcuate. transverse recesses I5, l5 in which the respective spring units II are received. The concavity of each recess I5 is complementa] to the convexity of the spring unit II received therein so that the bottom face of the recess rests iiush upon the top of the spring. In width, each recess may be slightly wider than the spring therein to enable relative movement between the spring and lateral faces of the recess upon deflection vof both, as weight 'is imposed upon the cushion structure. The material between the several recesses I5 constitutes ribs or piers I6 that bear upon the base member III and supplementthe springs II in supporting a superposed weight. The body structure I4 also bears upon the base memberl at the marginal region of the four sides thereof. As previouslyv stated, the body structure I4 is molded to the general shape of a cushion, which, as best shown in Figs. 2 and 3, is higher at the front (left) side thereof than it is at the rear (right), `with Vthe result that the top of ther structure slopes downwardly toward the rear. yAlso the front of the structure somewhat overhangs the base I 0, as shown, with the result that the highest point of the spring units II, which is midway between the ends thereof, will be located somewhat rearwardly of the transverse centerline of the cushion. The weight of a person seated on .a cush- "fe'ei throughout the entire extent of the regions above the spring units II, each of said regions is formed with a series of upwardly opening cavities or voids II, I8 arranged in the central plane of the underlying recesses I5. Said cavities i open onto the top face of the cushion, are of cylindrical shape and have rounded or heini-f sphericalbottoms. The said bottoms are spaced from the respective recesses I5 approximately the same distance as the highest points of said recesses are spaced from the top face of the cushion in the sitting area of the cushion, lwhere no recesses IB are provided. As shown in the drawing, each recess I5 has six recesses I8 thereover,

fiveof which recesses are at the front of the structure andare of diminishing 'depth rearwardlyA from the front margin thereof, there being but one recess I8 over each recess I5 at the rear of the structure. The recesses I8 will be covered over and obscured by upholstery material (not shown) in a finished seat.

In order that the cushion element I4 shall have uniform resilience or feel throughout its entire area, additional series of recesses or voids 20, 20 are'formed therein, which recesses. are substantially similar-in shape to the recesses Il. The recesses 20 are downwardly opening, and are located along the front-to-rear centerlines of the respective ribs or piers I6, and in the lateral regions of the cushion outwardly of the outermost recesses I5. The upper yextremities of the recesses 20 are spaced from the top of the cushion substantially the same distance as the thickness of the cushion structure over the spring units II at the highest elevation of the arc o! the latter. Because of the downwardl slope of the top of the cushion from front to rear thereof,

' the height of the recesses 20 progressively diminishes from the front to rear of each seri thereof.

In the operation of the supporting structure,

the ribs I6 and spring units II mutually coopcrate to support the weight of a person seated upon the structure. Upon compression resulting from a superposed load, the ribs I5 become more dense andV ultimately reach a point where further compression is not possible. At this point, however, the arc of the spring unitsII' is notcompletely iiattened, and they are still out of contact with the base member I0, above the latter. units II is to provide a feeling of lifeand resilience to the cushion regardless of -he degree of compression to which it is subjected. In this respect the K aden type springs employed are superior to conventional helical coiled springs since the latter become ineiiicient when compressed to half their normal length.`

Since the cushion member I4 is the element of greatest cost in the structure, the use of spring units II of the type shown results in a substantial cost saving due to the substantial volume of the recesses I5, and for the same reason there also is a substantial reduction in weight. The cushioning structure is of lower height than similar structures heretofore provided; it provides maximum comfort to a per- Ison seated thereon; and. achieves the other advantages set out in the foregoing statement of objects.

Modification may be resorted to without departing from the spirit of the invention, or the scope thereof as defined by the appended claims.

What is claimed is:` 'Y

v 1, A cushioning structure of the character de- An important function of the spring scribed comprising a fiat base member, a cushion of porous moldedL resilient material upon said base member formed on its under side with a plurality of parallel upwardly arched recesses extending in fore-and-aft direction, said recesses being laterally spaced apart from each other, arcuate upwardly extending transversely fiat spring units mounted on the base member and received in the respective cushion recesses so as yieldingly to resist deilection of the cushion, and a plurality of series of individualV voids extending downwardly into the cushion from the top side thereof, each of said series of voids disposed in the central plane of an underlying recess at the front and rear of the cushion.

2. A combination as deflned in claim 1 whereof the voids are of graduated depth, their bottoms being spaced from the arched recesses substantially the same distance as the thickness of the cushion material over the highest point of the recesses.

3. A combination as dened in claim 1 including a plurality of series of voids extending upwardly into the cushion material from the botltom side of the cushion, between and at each side oi' the spring-recesses therein.

HYLAND C. FLINT.

REFERENCES CITED The following references are of record in the flle of this patent: 

